CN105664972A

CN105664972A - Method for preparing sulfonated carbon nanotube solid acid catalyst with attapulgite as template

Info

Publication number: CN105664972A
Application number: CN201610001970.2A
Authority: CN
Inventors: 蒋金龙; 纪寿鹏; 许莹; 吴妹; 钱国庆; 陈静; 冯良东
Original assignee: Huaiyin Institute of Technology
Current assignee: Huaiyin Institute of Technology
Priority date: 2016-01-05
Filing date: 2016-01-05
Publication date: 2016-06-15

Abstract

The invention discloses a method for preparing a sulfonated carbon nanotube solid acid catalyst with attapulgite as a template. The method comprises the following steps: crushing attapulgite mineral, rolling the crushed attapulgite mineral, acidifying the rolled attapulgite mineral, carrying out pumping filtration on the acidified attapulgite mineral, washing the filtered attapulgite mineral with water, and freeze-drying the washed attapulgite mineral to obtain acidified attapulgite; carrying out vapor deposition on the acidified attapulgite to load furfuryl alcohol, charring the loaded acidified attapulgite, etching the charred acidified attapulgite to remove an attapulgite template, washing the obtained product with water, and drying the washed product to obtain amorphous carbon nanotubes; and processing the amorphous carbon nanotubes with concentrated sulfuric acid, washing the processed amorphous carbon nanotubes with water, and drying the washed amorphous carbon nanotubes to obtain the sulfonated carbon nanotube solid acid catalyst. The preparation method has the advantages of simplicity, low cost, and facilitation of a sulfonyl group due to low temperature incomplete charring of furfuryl alcohol, and the obtained sulfonated carbon nanotubes have high specific surface area and catalysis activity and good application prospect.

Description

A kind of method preparing Sulfonated carbon nanotube solid acid catalyst for template with attapulgite clay

Technical field

A kind of method that the present invention relates to Sulfonated carbon nanotube solid acid catalyst, specifically a kind of method preparing Sulfonated carbon nanotube solid acid catalyst for template with attapulgite clay.

Background technology

CNT has the electronics of uniqueness, mechanics and chemical characteristic, has a wide range of applications in fields such as composite, hydrogen storage material, electronic device, catalyst. CNT is carried out chemical modification by the nitration mixture adopting sulphuric acid or sulfonitric composition, can introduce sulfonic acid group in carbon nano tube surface, obtain hydrophilic carbon nano tube solid acid catalyst (ZL200410052406.0; Carbon, 2005,43,2397～2429). This solid acid catalyst has stronger acid catalytic property, it it is a kind of New Type of Carbon based solid acid catalyst, avoid and liquid acid use procedure exists side reaction is many, acid catalyst is not easily recycled, reactant need to neutralize that washing, corrosivity is big, the shortcoming of poor stability and bigger environmental pollution impact, environmental protection and being easily isolated, may replace the acid of the strongly corrosion liquid of sulphuric acid, hydrochloric acid, Fluohydric acid. etc and be applied in acid catalyzed reaction, there is bigger prospects for commercial application.

But, the Sulfonated carbon nanotube that existing research uses mostly is single wall or double-walled carbon nano-tube, the methods such as chemical vapour deposition (CVD) are adopted to prepare, specific surface area is less, limit the performance (AppliedCatalysisB:Environmental of Sulfonated carbon nanotube catalyst catalytic performance, 2014,147,726～732). Some mineral fibres such as attapulgite clay (hereinafter referred to as attapulgite clay), galapectite are template, amorphous carbon nanotube can be prepared after furfuryl alcohol low temperature vapor deposition load carbonization, removal template, its tube wall is formed (ZL201410088494.3 by amorphous nano-cluster, MicroporousandMesoporousMaterials, 2008,108,318～324). Compared with setting CNT (single wall or double-walled carbon nano-tube), the process employs natural clay template, with low cost, preparation method is simple, and has higher specific surface area (670～1000m²/ g), in fields such as catalyst, composite, hydrogen storage materials, there is potential using value.

Summary of the invention

It is an object of the invention to: the technology of a kind of Sulfonated carbon nanotube solid acid catalyst with cheap attapulgite clay for template preparation with high specific surface area, a kind of high performance carbon based solid acid catalyst of exploitation are provided.

The technical solution of the present invention comprises the following steps: first, and attapulgite clay mineral are size-reduced, pair roller, acidifying, sucking filtration, washing, obtain acidifying attapulgite clay after lyophilization; Then, acidifying attapulgite clay vapour deposition load furfuryl alcohol, obtain amorphous carbon nanotube through carbonization, etching liquid after removing attapulgite clay template, washing, drying; Finally, washing after gained amorphous carbon nanotube being adopted dense sulfuric acid treatment, drying obtain Sulfonated carbon nanotube solid acid catalyst.

The method of the present invention specifically comprises the following steps that

1) being ground by attapulgite clay mineral is 200 order sizes, and pair roller extrudes, and joins in 3mol/L hydrochloric acid solution with 10～20% solid-liquid mass volume ratios (g:mL); Transferring to after stirring in reactor, process 18～48h at 80 DEG C～180 DEG C, sucking filtration, washing repeatedly, are distributed in water according to 50% solid-liquid mass volume ratio, freeze-dried obtain acidifying attapulgite clay;

2) acidifying attapulgite clay is placed on narrow meshed politef pallet, pallet is placed in the middle part of politef, bottom such as is previously added at the quality bran alcohol, 130 DEG C process 6h, 300～400 DEG C of carbonization 2～4h under nitrogen protection subsequently, obtain C-attapulgite composite material, according to 1:8～12 mass volume ratio (g:mL), C-attapulgite composite material is added in etching liquid (HF acid or 2～5mol/LNaOH solution), transfer in reactor, 100～180 DEG C process 18～24h, a large amount of hot water is added after cooling, agitation and dilution, sucking filtration, washing is repeatedly, drying obtains CNT,

3) gained CNT is placed in reactor polytetrafluoroethyllining lining, concentrated sulphuric acid is added according to 1:10 mass volume ratio (g:mL), 5～10h is processed in 150～200 DEG C, after cooling, mixture in reactor is joined a large amount of hot dilution with water, sucking filtration, repeatedly wash gained black solid with hot water, finally dry and obtain Sulfonated carbon nanotube.

Compared with prior art, with natural clay fiber for template, gained Sulfonated carbon nanotube production cost is low for the present invention, and preparation method is simple, has higher specific surface area; Meanwhile, at a lower temperature the furfuryl alcohol of attapulgite clay surface deposition is carried out incomplete carbonization, be conducive to sulfonic acid group on the sulfonate graft of material with carbon element, therefore there is good catalysis activity.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is described in further detail. Should be understood that these embodiments present invention solely for the purpose of illustration, but not the scope being intended to limit the present invention in any manner.

Embodiment 1

Being ground by attapulgite clay mineral is 200 order sizes, and pair roller extrudes, and is joined by 5g attapulgite clay in 50mL3mol/L hydrochloric acid solution; Being transferred into after stirring in reactor, process 48h at 80 DEG C, sucking filtration, washing repeatedly, distribute it to, in 10mL water, obtain acidifying attapulgite clay after lyophilization. Being placed on narrow meshed politef pallet by 1g acidifying attapulgite clay, pallet is positioned in the middle part of politef, and bottom is previously added 1g furfuryl alcohol, and 130 DEG C process 6h, 300 DEG C of carbonization 4h under nitrogen protection subsequently, it is thus achieved that C-attapulgite composite material. Being added in 12mL2mol/LNaOH solution by 1gC-attapulgite composite material subsequently, transfer in reactor, 180 DEG C process 18h, add the dilution of a large amount of hot water after cooling, stir 30min, sucking filtration, and washing repeatedly, is dried and obtained CNT. 1g CNT is placed in reactor polytetrafluoroethyllining lining, 10mL concentrated sulphuric acid is added according to 1:10 mass volume ratio (g:mL), 150 DEG C process 10h, after cooling, mixture in reactor is joined in substantial amounts of hot water, sucking filtration, repeatedly wash gained black solid with hot water, finally dry and obtain Sulfonated carbon nanotube solid acid catalyst.

By 0.05g catalyst with 1mL oleic acid, 8mL methanol mixed uniformly, joining with in the round-bottomed flask of condensation reflux unit, magnetic agitation, reaction 4h at 65 DEG C, after product is performing centrifugal separation on, clear liquid adopts gas chromatographic detection, and oleic acid conversion is 80.3%.

Embodiment 2

Sulfonated carbon nanotube method for preparing catalyst is with example 1, and attapulgite clay consumption is 7g, and souring temperature is 150 DEG C, and the process time is 24h; Carbonization temperature is 350 DEG C, and carbonization time is 3h; Etching liquid is 10mL5mol/LNaOH solution, and sulfonation temperature is 180 DEG C, and sulfonation time is 8h, and other material usage and preparation condition are constant. Adopting catalytic performance method of testing described in example 1, oleic acid conversion is 82.5%.

Embodiment 3

Sulfonated carbon nanotube method for preparing catalyst is with example 1, and attapulgite clay consumption is 10g, and souring temperature is 180 DEG C, and the process time is 18h; Etching liquid is 8mL Fluohydric acid., and etching temperature is 100 DEG C, and etch period is 24h, and carbonization temperature is 400 DEG C, and carbonization time is 2h, and sulfonation temperature is 200 DEG C, and sulfonation time is 5h, and other material usage and preparation condition are constant. Adopting catalytic performance method of testing described in example 1, oleic acid conversion is 83.8%.

Claims

1. the method preparing Sulfonated carbon nanotube solid acid catalyst with attapulgite clay for template, it is characterised in that include step in detail below:

1) being ground by attapulgite clay mineral is 200 orders, and pair roller extrudes, and joins in 3mol/L hydrochloric acid solution; Transferring to after stirring in reactor, process 18～48h at 80 DEG C～180 DEG C, sucking filtration, washing repeatedly, are distributed in water according to 50% solid-liquid mass volume ratio, freeze-dried obtain acidifying attapulgite clay;

2) being placed on narrow meshed politef pallet by acidifying attapulgite clay, pallet is placed in the middle part of politef, and bottom such as is previously added at the quality furfuryl alcohol, 130 DEG C process 6h, subsequently carbonization under nitrogen protection, it is thus achieved that C-attapulgite composite material, C-attapulgite composite material is added in etching liquid, transferring in reactor, 100～180 DEG C process 18～24h, add a large amount of hot water after cooling, agitation and dilution, sucking filtration, washing repeatedly, is dried and is obtained CNT;

3) gained CNT is placed in reactor polytetrafluoroethyllining lining, adds concentrated sulphuric acid, process 5～10h at 150～200 DEG C, in following reaction still, mixture joins in a large amount of hot water, sucking filtration, repeatedly washs gained black solid with hot water, finally dries and obtains Sulfonated carbon nanotube.

2. the method for Sulfonated carbon nanotube solid acid catalyst according to claim 1, it is characterized in that the solid-liquid mass volume ratio (g:mL) of attapulgite clay and hydrochloric acid solution is 10～20%, souring temperature is 80～180 DEG C, and the acidification time is 18～48h, and drying means is lyophilization.

3. the method for Sulfonated carbon nanotube solid acid catalyst according to claim 1, it is characterised in that under nitrogen protection, carbonization temperature is 300～400 DEG C, carbonization time is 2～4h; The solid-liquid mass volume ratio (g:mL) of C-attapulgite composite material and etching liquid is 1:8～12, and etching liquid is Fluohydric acid. or 2～5mol/LNaOH solution, and etching temperature is 100～180 DEG C, and etch period is 18～24h.

4. the method for Sulfonated carbon nanotube solid acid catalyst according to claim 1, it is characterised in that CNT and concentrated sulphuric acid mass volume ratio (g:mL) are 1:10, and sulfonation temperature is 150～200 DEG C, and sulfonation time is 5～10h.